OMIM coverage of the taste receptor has the latest research and several related snps.
The U. Utah press release about the bitter taste SNP discovery
The paper on which the press release is based, stating that A49P and V262A are the key SNPs for nontaster/tasters, in that order.
A recent review, pointing out plenty of things, including the "amusing nature" of the taste test itself:
Note "tasting" is dominant over nontasting, so anyone who has at least one 49P (or 262A) SNP should be able to taste the test compounds (PTC or PROP).
Frequencies are high: 36% or more of the alleles in almost all human populations are "taster" alleles; therefore, since they are dominant, the majority of people tested should be able to taste bitter compounds.
The 3 SNPs in the TAS2R38 gene that form the taster/nontaster haplotypes are: